SharePoint Reservations

using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;

namespace RecurringClasses
{
    /// <summary>
    /// Concrete class to handle annually recurring events
    /// for example, 3rd of October
    /// J. Finn October 2008
    /// james.finn@gmail.com
    /// </summary>
    class YearlyRecurPeriod : absRecurPeriod
    {
        int yearFrequency = 0; // how many years between appointments
        int monthOfTheYear = 0; // month of the year
        int dayOfTheMonth = 0; // day of the month

        /// <summary>
        /// constructor sets up variables necessary to respond to GetNext
        /// </summary>
        /// <param name="StartDate">Start Date</param>
        /// <param name="EndDate">End Date</param>
        /// <param name="repeatNode">XML Node containing recurring definition</param>
        public YearlyRecurPeriod(ref DateTime StartDate, ref DateTime EndDate, XmlNode RepeatNode)
            : base(StartDate, EndDate)
        {

            // extracts values for yearFrequency, month of the year, and day of the month
            if (!Int32.TryParse(RepeatNode.Attributes["yearFrequency"].Value,
                out yearFrequency))
            {
                throw new Exception("Unexpected yearFrequency: " + RepeatNode.Attributes["yearFrequency"].Value);
            }
            
            if (!Int32.TryParse(RepeatNode.Attributes["month"].Value,
                out monthOfTheYear))
            {
                throw new Exception("Unexpected Day: " + RepeatNode.Attributes["day"].Value);
            }

            if (!Int32.TryParse(RepeatNode.Attributes["day"].Value, 
                out dayOfTheMonth))
            {
                throw new Exception("Unexpected Day: " + RepeatNode.Attributes["day"].Value);
            }
            

            // adjust start date to first selected day

            initialStartDate = new DateTime(this.initialStartDate.Year,
                                        monthOfTheYear, dayOfTheMonth,
                                        this.initialStartDate.Hour, this.initialStartDate.Minute,
                                        this.initialStartDate.Second);


            initialEndDate = new DateTime(this.initialEndDate.Year,
                                    monthOfTheYear, dayOfTheMonth,
                                    this.initialEndDate.Hour, this.initialEndDate.Minute,
                                    this.initialEndDate.Second);

            currentStartDate = initialStartDate;
            currentEndDate = initialEndDate;
        }

        /// <summary>
        /// Increments dates to get the next date in the recurrence pattern
        /// </summary>
        protected override void incrementDates()
        {
            currentStartDate = currentStartDate.AddYears(yearFrequency);
            currentEndDate = currentEndDate.AddYears(yearFrequency);

            if (currentStartDate.Day != dayOfTheMonth ||
                currentStartDate.Month != monthOfTheYear)
            {
                try
                {
                    currentStartDate = new DateTime(this.currentStartDate.Year,
                                            monthOfTheYear, dayOfTheMonth,
                                            this.currentStartDate.Hour, this.currentStartDate.Minute,
                                            this.currentStartDate.Second);


                    currentEndDate = new DateTime(this.currentEndDate.Year,
                                            monthOfTheYear, dayOfTheMonth,
                                            this.currentEndDate.Hour, this.currentEndDate.Minute,
                                            this.currentEndDate.Second);
                }
                catch (ArgumentOutOfRangeException ex)
                {
                    // invalid date leaves the original calculation
                }
            }
        }
    }
}